In heat exchangers having a plurality of heat exchanging tubes, it is often necessary to plug ends of a tube in order to isolate the tube from the remaining tubes of the heat exchanger. By doing so, a heat exchanger having a damaged tube can continue to operate, although with a reduced efficiency, until replacement or repair of the tube can be carried out. In view of the fact that replacement or repair of the one, or more tubes, usually requires extensive down-time for the heat exchanger and equipment dependent on it, a plurality of tubes can be plugged, over a period of time, in order to continue operation of the equipment. Replacement or repair of the damaged tubes can then be carried out at a planned shutdown of the equipment, for example. When plugging a tube, it is advantageous to use a plug and a means for installing the plug, which can allow plugging of the tube in an effective manner and in a minimum amount of time.
U.S. Pat. No. 5,437,310 teaches a plug for plugging a tube of a heat exchanger, in which a tapered wedge is used to expand a compressive ring into contact with an inner wall of the tube. A breakaway means is included with the plug in order to control the force exerted in a radial direction of the plug when it is installed. Removal of the plug is difficult.
The present invention provides a highly effective plug member for a heat exchanger tube and a drive means for installing and removing the plug member. The drive means automatically positions the plug member at a selected depth in the tube and automatically controls the pressure holding and sealing the plug member against an inner wall of the tube. Use of the system of the invention is easily carried out with one operator without a great deal of physical exertion required. The drive means can also be used for removing a plug member that has previously been installed. With use of the present system, a plug member can be installed in a matter of a few seconds. This feature can be very important when working in the area of a damaged nuclear reactor, for example, where minimizing exposure to radioactive material in a heat exchanger is important.